1. Field of the Invention
This invention relates to an IC card containing a CPU and a memory, for storing seat reservation data, for example, and a read/write control method for controlling the operation of reading out data stored in a memory contained in the IC card and writing data into the memory.
2. Description of the Related Art
In general, in order to prevent a third person other than the owner of an IC card from easily using the IC card, the operation of reading out and writing data with respect to the IC card is controlled by a password number. That is, if the same number as the password number previously registered in the IC card is not input, the read/write operation is inhibited.
A seat reservation system is an example of a system using the IC card. The seat reservation system is briefly explained below. First, the owner of the IC card, that is, a person who wants to make the seat reservation, inserts his own IC card into an IC card terminal provided on the street or in his house and then inputs the password number by use of the keyboard of the IC card terminal. If the input password number is correct, the IC card terminal connects a communication line between it and the central terminal and transmits data input by use of the keyboard indicating a desired section, desired data and the like to the central terminal by data communication. The central terminal informs the IC card terminal of the fact that the reservation has been accepted, and stores various reservation data into the IC card.
Thus, the reservation data is stored in the IC card and the owner may confirm the reservation data by inputting the password number using the keyboard of the IC card and specifying the identification of the reservation data (by depressing a specified key, for example) to display the reservation data on a display unit such as an LCD provided on the IC card.
In order to have the seat ticket issued, the owner goes to the ticket window of the service office and presents the IC card to the service office man. The office man or operator inserts the IC card into the ticket issuing machine and inputs the password number, then the ticket issuing machine accesses the IC card by use of the password number, reads out the reservation data and issues a ticket.
Since a single password number is given to each IC card, it is necessary for the owner of the IC card to inform the office man of the password number so that he can operate the ticket issuing machine and input the password number in order to have a ticket issued, and it is extremely inconvenient.
Further, since the office man may access the memory in the IC card after the office man has input the password number to access the IC card, it becomes possible for the office man to observe data such as personal data other than the reservation data.